Traditional additive manufacturing is a process of creating three-dimensional parts by depositing overlapping layers of material under the guided control of a computer. A common form of additive manufacturing is known as fused deposition modeling (FDM). Using FDM, a thermoplastic is passed through and liquified within a heated print head. The print head is moved in a predefined trajectory (a.k.a., a tool path) as the material discharges from the print head, such that the material is laid down in a particular pattern and shape of overlapping 2-dimensional layers. The material, after exiting the print head, cools and hardens into a final form. A strength of the final form is primarily due to properties of the particular thermoplastic supplied to the print head and a 3-dimensional shape formed by the stack of 2-dimensional layers.
A recently developed improvement over traditional FDM manufacturing involves the use of continuous fibers embedded within material discharging from the print head (a.k.a., Continuous Fiber 3D Printing—CF3D™). In particular, a matrix is supplied to the print head and discharged (e.g., extruded and/or pultruded) along with one or more continuous fibers also passing through the same head at the same time. The matrix can be a traditional thermoplastic, a powdered metal, a liquid matrix (e.g., a UV curable and/or two-part resin), or a combination of any of these and other known matrixes. Upon exiting the print head, a cure enhancer (e.g., a UV light, an ultrasonic emitter, a heat source, a catalyst supply, etc.) is activated to initiate and/or complete curing of the matrix. This curing occurs almost immediately, allowing for unsupported structures to be fabricated in free space. And when fibers, particularly continuous fibers, are embedded within the structure, a strength of the structure may be multiplied beyond the matrix-dependent strength. An example of this technology is disclosed in U.S. Pat. No. 9,511,543 that issued to Tyler on Dec. 6, 2016 (“the '543 patent”).
In some applications involving opaque fibers (e.g., carbon fibers), high-density fibers, high-concentrations of fibers, large-diameter fibers, etc., it can be difficult for the matrix material located at a center of the corresponding fiber bundle to receive sufficient cure enhancement (e.g., sufficient cure energy, catalyst, etc.). If unaccounted for, the resulting structure may lack strength and/or sag undesirably.
The disclosed system is directed to addressing one or more of the problems set forth above and/or other problems of the prior art.